Dry cell



June 7, 1927.

w. F. HENDRY DRY CELL Filed Nov. a, 1923 INVENTOR M F $8 ATTORNEY Patented June 7, 19 27. I UNITED STATES PATENT OFFICE- WILLIAM F. HENDRY, OF OS SINING, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO NATIONAL CARBON COMPANY, INC., YORK, N. Y., A CORPORATION OE NEW YORK.

" DRY CELL.

Application fi1ed November s, 1923. Serial n. 673,539.

This invention relates to dry cells and definite relation to the longest dimension of more particularly to a new and useful the graphite flakes. It is perfectly obvious m nner of preparing the depolarizing mix that if a quantity of a mixture containing v for dry ll 7 manganese dioxid, fine graphite and graph- It is the object of the present invention to ite flakes, approximately 3' in diameter, provide an improved dry cell mix in which was compressed to a thickness of 1 all flaked carbonaceous material, e. graphite, of the graphite flakes would lie flat and is used in a. new and improved manner toa dry battery made of an assembly of such geth r with a, it bl depolarizer u h a washers around the carbon electrode would In manganese di id; v have a much lower resistance than one made As is w ll know in th t, it i u to of the same mix tamped in the conventional any t i fin l ground k or a hit manner. It is evident that the turning over or other carbonaceous material with the Of these fl k s takes place at-the surfaces manganese dioxid for the reason that the g n t Wh ch he pressure is applied, and

latter is relatively a non-conductor and the therefore 1f the application of pressure was garbonaceous t i l i t du d ill dlscontmued before the mass was reduced to vid a th f ith current b t the t a thlckness less than the longest dimension pol s of th b tt Th fi th of the flake, a condition would result where bonaceous material is ground, the better it elhflakes eellaeeht t0 the Surfaces against coats the particles of depolarizing material, Whleh the P heeIl pp ied would but this fineness introduces innumerable e turned flatwlse, but these flakes in the contacts with consequent increase in resistfl 0f e Washer w uld be in random ance. To overcome this difliculty to some P as m the case of Ordinary extent, it has been common practice to in- 25 trodu a tit f t l hit i From this it" is evident that the benefit fl k f Th e fl k b i approxh to 'be 'derived fromthis construction is a mately in diameter, bridge over i function of the pressure applied and as numerable t t b t th ti l f there are practical l1m1ts to the density perfine r hit idi th plane f th missrble 1n a dry cell mix, the practical 30 flake is parallel with t 9 direction of definition of my invention would be a specirent fl th d i th l t i l fica'tlon setting forth the relation between sistance in the same manner that a sheet h thlekIless 0f the Washer and the longest of lead would reduce the electrical resistance (1111161181011 fl of a mass of bird h t The drawlngs represent in cross section an 35 In the conventional form of dry cell, the l g nd x gg r ed view of a portion mixture urrounding th c b n l t d of a dry cell constructed in accordance with is tamped or s ueezed into one compact mass he present lnvent on. substantially t e dimensions of the interior n ac ordance wlth the preferred embodiof the zinc container electrode and it is obment f th pr sent invention, the cell is 40 vious that with this method no o tr l h tcomposed of relatively thin washers like 1 soever an be xerci ed ove the o ition provlded within a zinc can 2'and surroundof the flakes 0r fl'ake graphite in the mix mg a carbon electrode 3. The Washers 1 in relation to the direction of current flow. are made of man anese dioxid, powdered Those which happen to lie with their longest graphite and flake graphite 4 placed under 45 dimension parallel to the flow of current a very high pressure. The manganese will aid in reducin the resistance, but all dioxid and powdered graphite are repreothefs will have litt e or no beneficial effect. sented by the blank spaces within washer 1.

The novel feature of my invention consists The graphite will, lie flat at substantially of a method of construction whereby a much right angles to the'longitudinal axes of the 5 greater proportion of the flakes are caused' two electrodes 2 and 3at those points of the 1 5 to assume the position with their greatest mix where the pressure is applied, i. e., the dimension parallel to the direction of curlower and upper surfaces of the washer 1. rent flow and this'is accomplished by squeez- Structures composed of similar washers are ing the mix in the form of flat tablets or described and claimed in my copending 55 washers, the thickness of which bears a application, Serial No. 654,611, filed July 30, 1923. Bysubjectin these washers to very high pressures, a p urality of substantially straight and continuous. layers of flaked graphite will be formed. The flakes in adjacent laiers will in all probability overlap each ot er thus aflording a straight .low resistance path for the electrical current from the carbon electrode 3 to the zinc electrode 2. I find that improved results are obtained when the thickness of these washers is even as much as six times the diameter of the flakes, though, of course, the

I best results are obtained with a much smaller ratio.

One of the advantages attained by the present invention is that as compared with the structure disclosed in my said applicaw I tion, it will not be necessary to apply a' coating-of graphite to the surfaces of the washers, the layers of graphite above referred to serving in the place of such coatings.

What I claim is: I ,1. A dry cell comprising tablets comnely ground and flaked conducting material.

2. A dry cell comprising tablets com-- 7 pacted of a depolarizer mixed with finely ground and flaked carbonaceous material. I

3.'A dry cell comprising compacted tablets of a mixture of manganese dioxid, powdered graphite, and flaked graphite.

4. A dry cell comprising compacted tablets of a depolarizing mix containing flaked carbonaceous material.

5. .A dry cell comprising tablets comacted of a depolarizer mixed with both pacted of depolarizing and conducting material, a portion of said conducting material being in the form of flakes.

6. A dry cell composed tablets compacted of depolarizing and conducting material, the upper and lower surfaces of each tablet being constituted by flaked conducting material compacted in a plurality of overlapping layers.

7 A dry cell composed of tablets the upper and, lower sunfaces of which are constituted by substantially continuous layers of flaked graphite.

' 8. A dry cell comprising tablets containing depolarizing and conducting material,

form, the rest of said carbonaceous mate-.

rial being in powder form and the position of a relatively large proportion of the flakes is such that the planes of the flakes are parallel to thedirection of current flow.

In witness whereof, I hereunto subscribe my name this7th day of November, 1923.

WILLIAM F. HENDRY.

of superimposed 

